JP2010187187A - Contact image sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long contact image sensor which can be made long by using a plurality of rod lens arrays, in which a drop in light quantity at a seam portion and deviation of an optical axis are reduced, and which is highly reliable. <P>SOLUTION: The image sensor is provided with: a light source for irradiating an object with light; rod lens arrays 80 which are arranged in a straight line so as to isolate individual rod lenses 81 for converging light that is reflected at or transmits the object, respectively, and are adjacently arranged such that rod lenses 80 located at the endmost part of the rod lenses 81 arranged in the straight line are brought into contact with each other; a light receiving element for receiving light image-formed on the rod arrays 80 over a predetermined reading width; and a frame 30 for fixing the plurality of rod lens arrays that are continuously arranged over the predetermined reading width via shock absorbing material 110, wherein rod lenses 81 of another rod lens array arranged adjacently in an area with a plurality of rod lenses 81 including the endmost part removed are interpolated, and a shielding adhesive 85 is applied to the interpolation area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a contact image sensor using a rod lens array used as an optical lens.

When a long contact image sensor is configured by connecting a plurality of inexpensive short rod lens arrays in a one-dimensional manner, a gap is generated at the joint portion of the rod lens array, resulting in a decrease in light quantity and resolution. Decrease. Further, since the joint portion is point contact, the optical axis is easily shifted in the sub-scanning direction, and it takes time to adjust the optical axis during the assembly process of the contact image sensor. For example, Japanese Patent Application Laid-Open No. 2005-217630, FIG. 4 (see Patent Document 1) discloses an image sensor in which rod lenses are brought into contact with each other using a single-row array type rod lens array.

Japanese Patent Application Laid-Open No. 2005-217630 discloses a case where rod lenses are connected by a two-row array type rod lens array. . In the connecting portion of the two-row array type rod lens array, the end processing region 84 is cut in an area half from the center of the rod lens to be connected, and the contact is only between the rod lenses.

JP 2005-217630 A

However, in the device described in FIG. 4 of Patent Document 1, the connecting portion of the rod lens array 80 is shaved in the end processing region 84 in an area half the center of the connecting lens, and the contact is the end of the rod lens 81. It is only between each other. Therefore, since the joint location is point contact, the adhesive strength is lowered due to secular change, and as a result, there is a problem that the optical axis is easily shifted in the sub-scanning direction.

Also in the thing of FIG. 5 of patent document 1, since a contact is only between the end parts of the rod lens 81, the adhesive strength falls by a secular change, As a result, the subject that an optical axis tends to shift | deviate in a subscanning direction. There is.

The present invention has been made in order to solve the above-described problems, and can be elongated by using a plurality of rod lens arrays, and can reduce the amount of light at the joint portion and the deviation of the optical axis. An object of the present invention is to provide a long contact type image sensor having a high height.

The contact image sensor according to the first aspect of the present invention is linearly arranged so as to isolate the light source that irradiates the subject with light and the individual rod lenses that collect the light reflected or transmitted by the subject. And a rod lens array arranged adjacent to each other so that rod lenses positioned at the extreme ends of the rod lenses arranged linearly contact each other, and light imaged by the rod lens array is received over a predetermined reading width. And a frame for fixing the plurality of rod lens arrays arranged in succession via a buffer material over the predetermined reading width, and the plurality of rod lenses including at least the outermost portion are continuously provided. Interpolating the rod lens of the other rod lens array that is placed adjacent to the removed area, and then applying this light-shielding adhesive to this interpolated area A.

According to a second aspect of the present invention, there is provided the contact image sensor according to the first aspect, wherein each of the rod lens arrays is fixed to the frame with respect to the center of the size in the optical axis direction.

The contact image sensor of the invention according to claim 3 is linearly arranged so as to isolate the light source that irradiates the subject with light and the individual rod lenses that collect the light reflected or transmitted by the subject. And a rod lens array arranged adjacent to each other so that rod lenses positioned at the extreme ends of the rod lenses arranged linearly contact each other, and light imaged by the rod lens array is received over a predetermined reading width. And a frame provided with a plurality of through-holes between the buffer material and a plurality of the rod lens arrays arranged in succession through the buffer material over the predetermined reading width. Forcibly attaching means inserted into the through hole, and another rod disposed adjacent to the region where the plurality of rod lenses including at least the outermost portion are continuously removed. Interpolating the rod lens of the lens array, it is to force fixing the arrangement of the rod lens array which are adjacent tightened the forced attachment means the interpolation region from both sides of the frame in a straight line.

According to a fourth aspect of the present invention, there is provided the contact image sensor according to the third aspect, wherein each of the rod lens arrays is fixed to the frame with respect to the center of the size in the optical axis direction.

According to the contact image sensor of claim 1, the rod lens of the other rod lens array arranged adjacent to the area where the plurality of rod lenses are continuously removed is interpolated, and the interpolated area has a light shielding property. Since the adhesive that we have is applied, the rod lens joint is firmly joined by surface contact, and it is possible to obtain a long and reliable contact image sensor with reduced detachment and poor adhesion due to aging. It becomes.

According to the contact type image sensor of claim 2, even if the thickness of each rod lens array varies in the optical axis direction, the thickness is fixed to the frame with respect to the center in the thickness direction of each rod lens array. It is possible to reduce the deterioration of the image due to the shift of the focal length.

According to the contact image sensor of the third aspect, since the optical axis of the rod lens array is focused at a position orthogonal to the conveyance direction of the subject, it is possible to prevent a reduction in resolution due to image blurring.

According to the contact image sensor of claim 4, even if the thickness of each rod lens array varies in the optical axis direction, it is fixed to the frame with reference to the center in the thickness direction of each rod lens array. It is possible to reduce the deterioration of the image due to the shift of the focal length.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration cross-sectional view of a contact image sensor according to Embodiment 1 of the present invention. It is a fragmentary top view of the peripheral part of the rod lens array mounted in the contact | adherence image sensor by Embodiment 1 of this invention. It is a top view which shows the shape of a commercially available rod lens array. It is a figure explaining the rod lens array of the contact | adherence type image sensor by Embodiment 1 of this invention, Fig.4 (a) is an edge part periphery figure of a 1 row arrangement type | mold rod lens array, FIG.4 (b) is processing. FIG. 4C is a diagram for explaining the method, and FIG. 4C is a diagram after the rod lens array is connected. It is a figure explaining the rod lens array of the contact | adherence type image sensor by Embodiment 1 of this invention, Fig.5 (a) is an edge part periphery figure of a 2 rows arrangement type | mold rod lens array, FIG.5 (b) is processing. FIG. 5C is a diagram for explaining the method, and FIG. 5C is a diagram after the rod lens array is connected. It is a figure explaining the rod lens array of the contact | adherence type image sensor by Embodiment 1 of this invention, Fig.6 (a) is an edge part periphery figure of a 3 rows arrangement type | mold rod lens array, FIG.6 (b) is processing. FIG. 6C is a diagram for explaining the method, and FIG. 6C is a diagram after the rod lens array is connected. 7A and 7B are configuration diagrams of a rod lens array of a contact image sensor according to Embodiment 2 of the present invention, in which FIG. 7A is a plan view and FIG. 7B is a side view. It is a structure sectional view of the contact type image sensor by Embodiment 3 of this invention. It is a partial cross section schematic diagram around the rod lens array of the contact image sensor according to Embodiment 3 of the present invention. It is a fragmentary top view of the rod lens array periphery of the contact | adherence image sensor by Embodiment 3 of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a contact image sensor according to Embodiment 1 of the present invention. In FIG. 1, 2 is a glass plate positioned on the traveling surface of a subject (such as a manuscript or bill), 6 is a line-type light source that illuminates the subject, 9 is a light receiving element (sensor IC) that receives light reflected by the subject, 10 is a sensor substrate on which the light receiving element 9 is placed, 11 is an L-shaped plate that supports the sensor substrate 10, 16 is a shielding member for preventing external light, and 18 is positioned above the contact image sensor, and the upper surface of the glass plate 2 A document (subject) that travels in the conveying direction relative to the contact image sensor, 30 is a frame that houses the glass plate 2, the light source 6, the sensor substrate 10, and the like, and includes a first frame 30a and a second frame 30b. . Reference numeral 80 denotes a rod lens array that converges (condenses) light sandwiched between the first frame 30a and the second frame 30b, and reference numeral 110 denotes a cushioning material provided in the reading width direction for bonding and fixing the frame 30 and the rod lens array 80 ( Double-sided tape).

FIG. 2 is a partial plan view of the periphery of the rod lens array 80 mounted on the contact image sensor according to Embodiment 1 of the present invention. In FIG. 2, 81 is an individual rod lens housed in a one-dimensional array so as to be linearly separated from each other in the rod lens array 80, 82 is a side plate sandwiching the rod lens 81, and one side plate 82a It consists of a side plate 82b on the other side. Reference numeral 83 denotes an adhesive that pseudo-fixes the rod lens 81 and the side plate 82. Reference numeral 85 denotes an adhesive that fills the ends of adjacent rod lens arrays and also serves as a light shield using a black resin or the like. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

Next, the joining of the rod lens array will be described. FIG. 3 is a plan view of a general-purpose (commercially available) rod lens array. Usually, end plates 86 are provided at both ends of the rod lens array. The shape shown in FIG. 3a is called a one-row arrangement type lens, the one shown in FIG. 3b is called a two-row arrangement type lens, and the one shown in FIG. 3c is called a three-row arrangement type lens. The mold lens has a staggered shape. The contact type image sensor of the present invention is intended to secure a long reading area having an effective reading width (predetermined reading width) exceeding 900 mm, and therefore, the commercially available rod lens array described in FIG. 3 is connected (bonded). ) For example, when a rod lens array having a width of 280 mm is used, three rod lens arrays and one rod lens array having a length shorter than 280 mm are joined to form a long rod lens array 80. 3, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

FIG. 4 is a diagram for explaining an example in which unnecessary portions of the rod lens array are deleted using two rod lens arrays, and FIG. 4A is a peripheral view of the end of the single-row array type rod lens array. 4 (b) is a process explanatory view showing the region (black portion A portion, B portion) of the side plate 82 to be removed by removing the termination plate 86 (indicated by the hatched portion). FIG. 4C is a diagram after connecting (joining) two rod lens arrays. 4, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

In the one-row array type lens shown in FIG. 3A, in the rod lens array 80 shown in the first embodiment, the pitch (p) between the rod lenses 81 is 0.7 mm, and the diameter (d) of the rod lenses 81 is 0. Since it is 6 mm, the gap between the rod lenses 81 is only 0.1 mm at maximum. Therefore, the rod lens 81 is removed when machining (milling). The milling of the end of the rod lens array is performed to remove the side plate 82 pieces and to remove the end plate 86.

In the first embodiment, the side plate 82 is removed by grinding (cutting) by milling so that the rod lens 81 can be processed regardless of whether the rod lens 81 is made of glass or transparent plastic. If it is glass, it may be carried out by laser processing.

The distance (size) of the side plate 82 to be removed varies depending on the connecting method of the rod lens 81 in the end portion processing region (A portion and B portion) shown in FIG. For the processing of one rod lens array, in the other side plate 82b end portion processing region (A portion), it is removed from the rod lens 81 at the endmost portion corresponding to several (assumed to be four). Further, in the end processing region (B portion) of one side plate 82a, the removal is performed up to the position before the rod lens 81 at the end.

On the other hand, with respect to the processing of the other rod lens array, the processing is performed up to the position before the rod lens 81 at the extreme end in the processing region (B portion) of the other side plate 82b. Further, in one end portion processing region (A portion) of one side plate 82a, removal is performed from the most end portion up to the position corresponding to the position of several rod lenses 81 (assumed to be four). After that, in one rod lens array, several (assuming four) rod lenses 81 are removed from the end.

Next, the unnecessary adhesive 83 having a small particle diameter, which has fixed the rod lens 81 and the side plate 82 before processing, is brushed around the portion located at the outermost portion and removed. Further, even at a portion where several rod lenses 81 shown in FIG. 4B (assumed to be four) are removed, they are removed by brushing.

Next, as shown in FIG. 4C, in order to obtain a rod lens array 80 in which processed single-row array lenses are connected to each other, another rod lens 81 aggregate is formed in a region where a plurality of rod lenses 81 are removed. It is confirmed that the adhesive 83 adhering to the side surface of each rod lens 81 is 0.05 mm or less. Thereafter, the other rod lens array 81 assembly is brought into contact with the removed rod lens 81 region of the one rod lens array, an adhesive 85 is newly applied to the processing region, and the side plate 82 and the rod lens 81 are moved in the longitudinal direction. A long rod lens array 80 is obtained by surface bonding along and fixing.

From the above, since the rod lens array is bonded to the surface by filling the adhesive 85 between the plurality of rod lenses 81 and the side plate 82 disposed oppositely through the rod lenses 81, the rod lens arrays are firmly fixed to each other. Thus, there is an effect of obtaining a long contact type image sensor in which a reduction in the amount of light at the joint portion and an optical axis shift are reduced.

  Next, a case where a two-row array type lens is processed will be described.

FIG. 5 is a diagram for explaining an example in which an unnecessary portion of the rod lens array is deleted using two rod lens arrays, and FIG. 5A is a peripheral view of the end of the two-row array type rod lens array. FIG. 5 (b) is a processing diagram showing the region (black portion A portion, B portion) of the side plate 82 to be removed by removing the end plate 86 (indicated by a hatched portion). FIG. 5C is a diagram after connecting (joining) two rod lens arrays. 5, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

In the two-row arrangement type lens shown in FIG. 3b, in the rod lens array 80 shown in the first embodiment, the pitch (p) between the rod lenses 81 is 0.7 mm, and the diameter (d) of the rod lenses 81 is 0. Since it is 6 mm, the gap between the rod lenses 81 is only 0.1 mm at maximum. Therefore, the rod lens 81 is removed when machining (milling). The milling of the end of the rod lens array is performed to remove the side plate 82 pieces and to remove the end plate 86.

In the first embodiment, the side plate 82 is removed by grinding (cutting) by milling so that the rod lens 81 can be processed regardless of whether the rod lens 81 is made of glass or transparent plastic. If it is glass, it may be carried out by laser processing.

5B, the distance (size) of the side plate 82 to be removed differs depending on the connecting method of the rod lens 81. In the end machining region (A portion, B portion) shown in FIG. For the processing of one rod lens array, in the other side plate 82b end portion processing region (A portion), it is removed from the rod lens 81 at the endmost portion corresponding to several (assumed to be four). Further, in the end processing region (B portion) of one side plate 82a, the removal is performed up to the position before the rod lens 81 at the end.

On the other hand, with respect to the processing of the other rod lens array, the processing is performed up to the position before the rod lens 81 at the extreme end in the processing region (B portion) of the other side plate 82b. Further, in one end portion processing region (A portion) of one side plate 82a, removal is performed from the most end portion up to the position corresponding to the position of several rod lenses 81 (assumed to be four). Thereafter, several (temporarily four) rod lenses 81 are removed from the outermost ends of the rod lenses 81 of different series in each of the two rod lens arrays that are arranged in two rows in a staggered pattern. That is, in one rod lens array, several (four temporarily) rod lenses 81 are removed from the endmost portion on the other side plate 82b side. Further, in the other rod lens array, several (for example, four) rod lenses 81 are removed from the endmost portion on the side plate 82a side.

Next, the unnecessary adhesive 83 having a small particle diameter, which has fixed the rod lens 81 and the side plate 82 before processing, is brushed around the portion located at the outermost portion and removed. Further, even at a portion where several rod lenses 81 shown in FIG. 5b (assumed to be four) are removed, they are removed by brushing.

Next, as shown in FIG. 5C, in order to obtain a rod lens array 80 in which the two-row arrayed lenses after processing are connected to each other, they are attached to a region where a plurality of rod lenses 81 of different systems are removed. It is confirmed that the adhesive 83 is 0.05 mm or less on the side surface of each rod lens 81 of the rod lens 81 aggregate. Thereafter, both rod lens array 81 aggregates are brought into contact with the removed rod lens 81 region in a zigzag manner, and an adhesive 85 is newly applied to the processing region, and the side plate 82 and the rod lens 81 are moved in the longitudinal direction. A long rod lens array 80 is obtained by surface bonding along and fixing.

From the above, the rod lens array is surface-bonded in a staggered configuration by filling the adhesive 85 between the plurality of rod lenses 81 and the side plate 82 disposed oppositely through the rod lenses 81. There is an effect of obtaining a long contact type image sensor in which the members are firmly fixed to each other and the reduction in the amount of light at the joint portion and the shift of the optical axis are reduced.

Next, processing of a three-row array type lens will be described.

FIG. 6 is a diagram for explaining an example in which the unnecessary portion of the rod lens array is deleted using two rod lens arrays, and FIG. 6A is a peripheral view of the end of the three-row array type rod lens array. 6 (b) is a processing diagram showing the region (black portion A portion, B portion) of the side plate 82 to be removed by removing the end plate 86 (indicated by a hatched portion). FIG. 6C is a diagram after connecting (joining) two rod lens arrays. 6, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

In the three-row array type lens shown in FIG. 3c, in the rod lens array 80 shown in the first embodiment, the pitch (p) between the rod lenses 81 is 0.7 mm, and the diameter (d) of the rod lenses 81 is 0. Since it is 6 mm, the gap between the rod lenses 81 is only 0.1 mm at maximum. Therefore, the rod lens 81 is removed when machining (milling). The milling of the end of the rod lens array is performed to remove the side plate 82 pieces and to remove the end plate 86.

In the first embodiment, the side plate 82 is removed by grinding (cutting) by milling so that the rod lens 81 can be processed regardless of whether the rod lens 81 is made of glass or transparent plastic. If it is glass, it may be carried out by laser processing.

6B, the distance (size) of the side plate 82 to be removed differs depending on the connecting method of the rod lens 81. In the end machining region (A portion, B portion) shown in FIG. For the processing of one rod lens array, in the other side plate 82b end processing region (A portion), it is removed from the rod lens 81 at the endmost portion corresponding to several (assumed to be five). Further, in the end processing region (B portion) of one side plate 82a, the removal is performed up to the position before the rod lens 81 at the end.

On the other hand, with respect to the processing of the other rod lens array, the processing is performed up to the position before the rod lens 81 at the extreme end in the processing region (B portion) of the other side plate 82b. In addition, in one side plate 82a end portion processing region (A portion), it is removed from the endmost portion to the position corresponding to several (assuming five) rod lenses 81.

Thereafter, several rod lenses 81 (temporarily five) are removed from the outermost ends of the rod lenses 81 of different series in each of the three rod lens arrays that are arranged in three rows in a staggered pattern. Further, several (for example, two) rod lenses 81 are removed from the extreme ends of both rod lens arrays in the center of the three systems. That is, in one rod lens array, several rod lenses 81 (assumed to be five) are removed from the endmost portion on the other side plate 82b side. In the other rod lens array, several (assumed to be five) rod lenses 81 are removed from the endmost portion on the side plate 82a side. Then, several (for example, two) rod lenses 81 are removed from the end portions of both rod lens arrays separated from the side plate 82.

Next, the unnecessary adhesive 83 having a small particle diameter, which has fixed the rod lens 81 and the side plate 82 before processing, is brushed around the portion located at the outermost portion and removed. 6B is removed by brushing even at a portion where several rod lenses 81 (assumed to be five) are removed.

Next, as shown in FIG. 6 (c), a rod lens 81 aggregate attached to a region from which a plurality of rod lenses 81 are removed in order to obtain a rod lens array 80 in which processed three-row array lenses are connected to each other. It is confirmed that the adhesive 83 is 0.05 mm or less on the side surface of each rod lens 81. Thereafter, both rod lens array 81 aggregates are brought into contact with the removed rod lens 81 region in a zigzag manner, and an adhesive 85 is newly applied to the processing region, and the side plate 82 and the rod lens 81 are moved in the longitudinal direction. A long rod lens array 80 is obtained by surface bonding along and fixing.

From the above, the rod lens array is surface-bonded in a staggered configuration by filling the adhesive 85 between the plurality of rod lenses 81 and the side plate 82 disposed oppositely through the rod lenses 81. There is an effect of obtaining a long contact type image sensor in which the members are firmly fixed to each other and the reduction in the amount of light at the joint portion and the shift of the optical axis are reduced.

In the first embodiment, interpolation is performed with the rod lens 81 of the other rod lens array that is arranged adjacent to the region where the plurality of rod lenses 81 including the outermost portion are continuously removed. The rod lens 81 of the other rod lens array may be removed as appropriate. Then, a light-shielding adhesive is applied to this interpolation area.

Next, the assembly order of the contact image sensor will be described. In FIG. 2, the double-sided tape 110 is attached to the frame 30. In FIG. 2, the double-sided tape 110 is continuous. However, even if there is no double-sided tape in part, it may be almost continuous. The reason for the continuous fixing is as follows. When a temperature change is applied to the image sensor, a dimensional difference is generated on the reading width (longitudinal) direction side due to a difference in thermal expansion coefficient between the frame 30 and the rod lens array 80. As a result, stress is applied to the rod lens array 80. Therefore, stress is absorbed by fixing the rod lens array 80 with the double-sided tape 110 over almost the entire length in the longitudinal direction. On the other hand, when partial fixing is performed, the stress is concentrated in the fixed portion, but the stress is concentrated in the non-fixed portion, and the rod lens arrays 80 are bonded to each other unless the joint portion of the rod lens array 80 is bonded. A great stress is generated at the joint portion.

Next, the surface opposite to the side from which the end of the rod lens array is removed is aligned with the double-sided tape 110 that is previously attached to the frame 30a, and then machine (jig) bonding is performed. Thereafter, similarly processed rod lens arrays are combined with each other, and after positioning the lens, machine (jigs) are bonded. Further, when three or more rod lens arrays are connected, the end processing of the central rod lens array that is not located at both ends is processed so as to be pointed. At the time of bonding, an adhesive 85 that also serves as a light shield is applied so as to fill a gap between portions where the rod lenses 81 are in contact with each other. By applying the adhesive 85 that also serves as a light shield, the light shield effect of the portion where the rod lens 81 is partially exposed is improved. The coating width is a portion where the rod lenses 81 are in contact with each other and a portion where the rod lenses 81 are exposed. The coating height is preferably applied over the entire height of the rod lens 81 in the optical axis direction. However, if the coating height is relatively short, even if the coating height is about half of the height of the rod lens 81. good.

In the first embodiment, a silicone resin adhesive is used as the adhesive 85 that also serves as a light shield in order to have a soft adhesive effect. Also, black is used to prevent light leakage from the rod lens 81 and external light from entering, but the light shielding performance can be secured even if it is a semi-turbid color if it is not transparent for the light shielding effect.

In the first embodiment, the rod lens array 80 is attached to the frame 30 using the double-sided tape 110. However, the rod lens array 80 may be attached to one side of the frame 30. In addition, the connection between the rod lens arrays 80 is described with respect to two adjacent ones in FIG. 2, but since the purpose is to obtain a long image sensor, both ends of the rod lens array 80 are adjacent rod lenses. Since it is connected continuously with the array 80, three or more rod lens arrays 80 may be connected linearly.

As described above, in the first embodiment, the end portion of the rod lens array of the general-purpose size is processed, and the end rod lens 81 of each rod lens array and several rod lenses 81 are in contact with each other. Then, the rod lens array 80 is fixed over almost the entire length of the frame 30, the gap between the rod lens arrays is filled, and an adhesive 85 that also serves as a light shield is filled, so that light does not pass from other than the rod lens 81. Therefore, image blurring at the bonded portion is reduced, and it is not necessary to use a commercially available long rod lens array, and it is possible to realize a high-quality long image sensor using an inexpensive rod lens array. .

In the first embodiment, the individual rod lens arrays are sequentially attached to the frame 30 and fixed. However, the rod lens arrays are first connected to each other, and the rod lens array having a desired length is fixed to the frame. This will be described in Embodiment 2.

Embodiment 2. FIG.
Embodiment 2 of the present invention will be described with reference to the drawings. 7A and 7B are configuration diagrams of the rod lens array of the contact image sensor according to Embodiment 1 of the present invention. FIG. 7A is a plan view and FIG. 7B is a side view. In FIG. 7, 80 a, 80 b and 80 c denote individual rod lens arrays, which are connected to form the rod lens array 80. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts.

In general, a commercially available rod lens array has a variation of about ± 0.05 mm in the thickness (Z) in the height direction of the rod lens array main body forming a part of the conjugate length (TC) that determines the reading focus. Therefore, when connecting the rod lens arrays 80 having different heights (thicknesses), when the focus is adjusted on the basis of the upper or lower surface in the height direction, the optimum focal positions in the respective rod lens arrays are different. . Therefore, it is necessary to adjust so that it becomes a position close | similar to a focus optimal position in each rod lens array.

In order to solve this problem, the rod lens arrays are connected so that the center positions of the rod lenses 80 in the height direction coincide with each other. In the second embodiment, a long rod lens array is not pasted on the frame 30a, but the short rod lens arrays are pasted together to obtain a desired length, and then joined to the desired length. The lens array 80 is aligned with a double-sided tape 110 that has been previously affixed to the frame 30a or the like, and is then bonded to a machine (jig).

That is, in the assembly described in the first embodiment, it is difficult to connect the rod lens array 80 at different centers in the height direction, but the rod of the rod lens array 80 can be connected by using the method of the second embodiment. It becomes easy to connect the centers in the height direction using an apparatus specialized for attaching the lens array. Thereby, a change in resolution in the main scanning direction of the connection portion can be reduced.

In the second embodiment, the method of connecting the rod lenses first is described, but in the third embodiment, the reinforcement around the rod lens connecting portion after the rod lens array 80 incorporated in the contact image sensor is described.

Embodiment 3 FIG.
Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 8 is a sectional view showing the structure of a contact image sensor according to Embodiment 3 of the present invention. In FIG. 8, reference numeral 130 denotes a lens connection portion reinforcing screw, 130a denotes a reinforcing screw installed on the frame 30a side, and 130b denotes a reinforcing screw installed on the frame 30b side. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

Next, the operation will be described. FIG. 9 is a partial cross-sectional schematic view around the rod lens array of the contact image sensor according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. The rod lens 80 incorporated in the frame 30 provided with the through hole is fixed by a reinforcing screw 130. When short rod lens arrays are connected to each other, they are connected by an adhesive 85 that also serves as a light shield. However, when used for a long period of time, there is a possibility that the corresponding part may be peeled off due to a temperature change or the like. Further, the position of the rod lens array 80 is fixed by the buffer material (double-sided tape) 110 and the frame 30, but the buffer material (double-sided tape) 110 is compressed and expanded. Therefore, there is a possibility that the optical axis of each rod lens array is displaced near the bonded portion, and the optical performance is affected.

In order to prevent these peelings, a reinforcing screw 130 is installed from the side surface in the vicinity of the adhesion of the rod lens array 80. The tightening torque of the reinforcing screw 130 is determined by the size, material, and strength of the frame 30 constituting the contact image sensor. Further, although the reinforcing screw 130 is tightened from both directions of the frame 30, even if it is tightened from one side, the cushioning material (double-sided tape) 110 is an elastic body, and thus has a corresponding effect.

FIG. 10 is a partial plan view of the periphery of the rod lens array of the contact image sensor according to the third embodiment of the present invention. That is, FIG. 10 is a view from the upper surface of the rod lens array shown in FIG. 9, and is a peripheral view of a connection (joining) portion of the two-row arrangement type rod lens array 80. The connecting portion of the rod lens array 80 is reinforced by the reinforcing screw 130 from the side surface. One reinforcing screw 130 may be provided from one side of each of the reinforcing screws 130 around the ends of the adjacent rod lens arrays. Further, instead of the reinforcing screw 130, a forcible attachment means 130 such as a block-like or plate-like spring or pin may be used.

As described above, according to the third embodiment, it is possible to improve image blurring and peelability at each connection portion (connection portion) of the rod lens array 80 that is continuously installed. That is, the interpolation region in which a plurality of rod lenses including the endmost portion are continuously removed is clamped from both sides of the frame 30 by the forcibly attaching means, and the alignment of adjacent rod lens arrays is forcibly fixed linearly. Is completely perpendicular to the document 1.

According to the third embodiment, the sticking of the rod lens lens array around the connecting portion is forcibly attached according to the bonding strength and reliability between the rod lens arrays or the required specifications. Using the means 130, instead of applying the adhesive 85 described in the first embodiment, the side plate 82 is clamped by the forcible attachment means from both sides with the rod lens array 80 sandwiched by using the forcible attachment means 130. It is also possible to omit the application of the agent 85.

As described above, according to the close contact type image sensor according to the third embodiment, image blurring at the bonding portion is reduced, and a plurality of inexpensive rod lens arrays are connected without using a long rod lens array, thereby achieving high image quality. Thus, a long image sensor can be realized.

The processing and assembling method of the rod lens array 80 of the contact image sensor described in the first to third embodiments of the present invention includes a rod lens array used in an image writing apparatus that requires a relatively long length and a general copying machine. It can also be applied to the close contact type image sensor.

In the first to third embodiments, the light source 6 accommodated in the housing 30 of the contact image sensor has been described. However, the light source is provided at a position facing the contact image sensor via the document 1 and the document 1 is transmitted therethrough. The light may be collected by the rod lens array 80.

2..Glass plate 6..Light source 9..Light receiving element (sensor IC)
10 .... Sensor board 11 .... L-shaped plate 16 .... Resin (light shielding member)
18. Manuscript (subject)
30 ·· Frame (housing) 30a · · First frame 30b · · Second frame 80 · · Rod lens array 80a · · Individual rod lens array 80b · · Individual rod lens array 80c · · Individual rod lens array 81..Rod lens 82..Side plate 82a..Side plate on one side 82b..Side plate 83 on the other side..Adhesive (pseudo-adhesive) 85..Adhesive (adhesive that also serves as a light shield)
86..Terminal plate 110..Buffer material (double-sided tape)
130. ・ Forced attachment means (reinforcement screw for connection part)
130a ... Forced attachment means on one side 130b ... Forced attachment means on the other side

Claims (4)

The light source that irradiates light to the subject and the individual rod lenses that collect the light reflected or transmitted by the subject are linearly arranged so as to be isolated, and the rod lenses that are linearly arranged A rod lens array arranged adjacent to each other so that rod lenses located at the ends are in contact with each other, a light receiving element that receives light imaged by the rod lens array over a predetermined reading width, and a plurality of continuously arranged light receiving elements A rod for fixing the rod lens array through a buffer material over the predetermined reading width, and the other rod disposed adjacent to a region where a plurality of rod lenses including at least an end portion are continuously removed. A contact type image sensor in which a rod lens of a lens array is interpolated and a light-blocking adhesive is applied to the interpolation area. 2. The contact image sensor according to claim 1, wherein each of the rod lens arrays is fixed to the frame with respect to a center in a size in an optical axis direction. The light source that irradiates light to the subject and the individual rod lenses that collect the light reflected or transmitted by the subject are linearly arranged so as to be isolated, and the rod lenses that are linearly arranged A rod lens array arranged adjacent to each other so that rod lenses located at the ends are in contact with each other, a light receiving element that receives light imaged by the rod lens array over a predetermined reading width, and a plurality of continuously arranged light receiving elements The rod lens array includes a frame provided with a plurality of through holes between the buffer material and fixing the rod lens array over the predetermined reading width, and a forced attachment means inserted into the through holes, Interpolate the rod lens of the other rod lens array adjacent to the region where the plurality of rod lenses including at least the outermost portion are continuously removed, and compensate for this. Contact image sensor to force fixing the arrangement of the rod lens array which are adjacent tightened the forced attachment means an area on both sides of the frame in a straight line. The contact type image sensor according to claim 3, wherein each of the rod lens arrays is fixed to the frame with respect to the center of the size in the optical axis direction.

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